Process and plant for producing tyres for vehicle wheels

ABSTRACT

A plant and a process for producing tyres for vehicle wheels includes the steps of a) building a tyre on a toroidal support in a building line of a production plant; b) moulding and vulcanizing the assembled tyre in a vulcanization line of the production plant; c) transferring by means of a first transfer device the toroidal support and the relevant moulded and vulcanized tyre to a working station including a removing unit for removing the tyre from the respective toroidal support and a cooling unit for cooling the toroidal support; d) removing the moulded and vulcanized tyre from the relevant toroidal support in the removing unit; e) transferring the toroidal support from the removing unit to the cooling unit by means of a second transfer device different from the first transfer device; and f) cooling the toroidal support in the cooling unit.

The object of the present invention is a process for producing tyres forvehicle wheels.

In particular, the present invention relates to a process for producingtyres built on a toroidal support.

It is also an object of the invention a plant for producing tyres forvehicle wheels, able to be used for carrying out the aforementionedproducing process.

Modern production cycles of a tyre provide that, after a buildingprocess wherein the various components of the same tyre are made and/orassembled in a building line, a moulding and vulcanization process iscarried out, in a suitable vulcanization line, adapted for defining thetyre structure according to a desired geometry and tread pattern.

A tyre generally comprises a toroidally ring-shaped carcass includingone or more carcass plies, strengthened with reinforcing cords lying insubstantially radial planes (a radial plane contains the rotation axisof the tyre). Each carcass ply has its ends integrally associated withat least one metal reinforcing annular structure, known as bead core,constituting the reinforcing at the beads, i.e. at the radially innerends of the tyre, having the function of enabling the assembling of thetyre with a corresponding mounting rim. Placed crown wise to saidcarcass is a band of elastomeric material, called tread band, withinwhich, at the end of the moulding and vulcanization steps, a raisedpattern is formed for ground contact. A reinforcing structure, generallyknown as belt structure, is arranged between the carcass and the treadband. Such structure usually comprises, in the case of car tyres, atleast two radially superposed strips of rubberised fabric provided withreinforcing cords, usually of metal material, arranged parallel to eachother in each strip and in a crossed relationship with the cords of theadjacent strip, preferably symmetrically arranged with respect to theequatorial plane of the tyre. Preferably, the belt structure furthercomprises at a radially outer position thereof, at least on the ends ofthe underlying belt strips, also a third layer of textile or metalliccords, circumferentially disposed (at zero degrees).

Finally, in tyres of the tubeless type, that is devoid of an air tube, aradially inner layer, called liner, is present which has imperviousnessfeatures for ensuring the air-tightness of the tyre itself.

To the aims of the present invention and in the following claims, by theterm “elastomeric material” it is intended a composition comprising atleast one elastomeric polymer and at least one reinforcing filler.Preferably, such composition further comprises additives such ascross-linking and/or plasticizing agents. By virtue of the cross-linkingagents, such material may be cross-linked by heating, so as to form thefinal manufactured article.

In recent times, tyre production processes in which a green tyre isbuilt on a rigid toroidal support have been introduced in the field.Said processes are preferably used for tyres produced starting from alimited number of elementary semifinished products fed onto saidtoroidal support whose outer profile coincides with that of the radiallyinner surface of the tyre to be produced. The toroidal support is moved,preferably by means of a robotized system, among a plurality of workingstations in each of which a particular building step of the tyre iscarried out, through automated sequences. At the end of the buildingsteps, the toroidal support with the green tyre supported thereby isarranged inside a vulcanization mould.

In the present context, by the term “green tyre” it is indicated a tyreobtained by the building process and still to be vulcanized.

An example of the above processes is described in WO 01/32409, in thename of the same Applicant, which illustrates a tyre building lineprovided with working stations, each arranged to make and assemble atleast one structural component of the tyre being processed, wherein atleast one series of tyres, comprising at least a first and a secondmodel of tyres that are different from each other, is treatedsimultaneously, and wherein the transferral of the tyres to thevulcanization line is carried out through robotized arms and accordingto a transferring rate which is equal to the transferring rate of thetyres to each of said working stations.

On the other hand WO 01/39963, in the name of the same Applicant,illustrates a process for producing tyres that are different from eachother, comprising a building unit having a plurality of workingstations, each adapted for assembling at least one structural componenton at least one type of tyre being processed, a vulcanization unit, anda device for transferring and moving the tyre being processed, operatingbetween the working stations and the vulcanization unit.

Said device for transferring and moving the tyre transfers a green tyrefrom the building unit to the vulcanization unit; after vulcanization,it picks up a vulcanized and moulded tyre from the vulcanization unitand moves it to the first working station of the building unit, wherethe tyre is removed from the corresponding toroidal support. The latteris then moved by the same device for transferring and moving the tyreinto a temperature stabilizing device. If the tyre to be producedrequires a toroidal support of a different type, the same device picksup the suitable toroidal support from a feeding station and introducesit into the temperature stabilizing device.

The Applicant has noted that since the above device for transferring andmoving the tyre is arranged for carrying out numerous operations andmaking wide displacements, it is often the bottleneck of the producingprocess. For example, making tyres differing from one another asillustrated in WO 01/39963, due to the different cooling times requiredby the toroidal supports and to the variability of the operating timesof the building line, the transfer device may have to carry out repeatedtransfers of the toroidal support between one temperature stabilizingstation and a stand-by position.

Moreover, the processes described above do not allow an optimumdistribution of the production times, nor an optimum management of thetransfer device since the repeated transfers of the toroidal support bymeans of said device, from a cooling station to the next cooling stationor from a cooling station to a stand-by position, require the use ofsuch device for unduly long times, thus decreasing the flexibility andthe production capacity of the production plant.

The Applicant has then noted that the pathway accomplished by thetransfer device are excessively long with consequent increase of thecomplexity of the production plant.

The Applicant has therefore perceived that by decreasing the number oftransfers of the toroidal support it is possible to obtain a simplerproducing process that allows to increase the productivity of a plantfor producing tyres for vehicle wheels built on a toroidal support, aswell as the layout simplicity thereof.

The Applicant has therefore found that by integrating the unit forremoving the tyre from the toroidal support and the unit for cooling thesame toroidal support into a single working station it is possible todecrease the work load of the transfer device obtaining a more flexibleand efficient producing process.

In accordance with a first aspect thereof, the invention relates to aprocess for producing tyres for vehicle wheels comprising the steps of:

a) building a tyre on a toroidal support in a building line of aproduction plant;b) moulding and vulcanizing said built tyre in a vulcanization line ofsaid production plant;c) transferring by a first transfer device the toroidal support and therelevant moulded and vulcanized tyre to a working station comprising aremoving unit for removing the tyre from the respective toroidal supportand a cooling unit for cooling the toroidal support;d) removing the moulded and vulcanized tyre from the relevant toroidalsupport in said removing unit;e) transferring the toroidal support from said removing unit to saidcooling unit by a second transfer device different from said firsttransfer device;f) cooling the toroidal support in said cooling unit.

Such process allows to solve the aforementioned problems and to achievea decrease of the work load of the first transfer device with consequentimprovement of the efficiency.

Advantageously, after the step f) of cooling the toroidal support, theprocess comprises the step g) of transferring the cooled toroidalsupport outward the working station by means of the first transferdevice.

Preferably, the step f) of cooling the toroidal support comprises thesub-steps of:

f1) cooling the toroidal support to a temperature comprised betweenabout 100° C. and about 110° C.;f2) cooling the toroidal support to a temperature comprised betweenabout 55° C. and about 65° C.;f3) cooling the toroidal support to a temperature suitable for the tyrebuilding process;

In a preferred embodiment, step f3) provides cooling the toroidalsupport to a temperature comprised between about 40° C. and about 50° C.

Step f1) is preferably carried out with cooling water, advantageouslynebulized and sprayed at the outer surface and at the inner surface ofthe toroidal support.

Preferably, at least one between steps f2) and f3) is carried out withcooling air, advantageously dispensed at the top surface, at the bottomsurface and at the outer surface of the toroidal support.

According to a preferred embodiment, the step e) of cooling the toroidalsupport in the cooling unit comprises the sequential transfer of thetoroidal support in at least three specialised stations differing onefrom the other.

Said sequential transfer is advantageously accomplished by a thirdtransfer device, different from the first transfer device and from thesecond transfer device.

Said third transfer device preferably comprises a conveyor belt or arobotized arm.

As an alternative, the sequential transfer of the toroidal support fromone specialised station to the next one is carried out by the firsttransfer device.

Preferably, the above step d) of removing the moulded and vulcanizedtyre from the relevant toroidal support comprises the sub-steps of

d0) extracting a support shaft of said toroidal support;d1) dismounting the toroidal support;d2) separating the vulcanized tyre from the toroidal support;d3) remounting the toroidal support;d4) inserting said support shaft into the remounted toroidal support.

Advantageously, at least one between step d0) and d4) is carried out bymeans of said second transfer device.

As an alternative, at least one between said steps d1), d2) and d3) iscarried out by means of a device for dismounting/remounting the toroidalsupport.

According to a preferred embodiment, the step g) of transferring thecooled toroidal support outward the working station is followed by astep h) of introducing the toroidal support into the building line forbuilding a further tyre.

In accordance with a second aspect thereof, the invention relates to aplant for producing tyres for vehicle wheels comprising:

-   -   a line for building a green tyre on a respective toroidal        support;    -   a line for moulding and vulcanizing the tyre;    -   at least one working station interposed between said building        line and said moulding and vulcanization line;    -   at least a first transfer device for transferring the moulded        and vulcanized tyre and the respective toroidal support into        said working station;    -   wherein said working station comprises:    -   at least one removing unit for removing the moulded and        vulcanized tyre from the respective toroidal support;    -   at least one cooling unit for cooling the toroidal support; and    -   at least a second transfer device of the toroidal support        different from the first transfer device, for transferring the        toroidal support from the tyre removing unit to the toroidal        support cooling unit.

Such plant solves the above problems relating to the overload of thetransfer device and therefore it is flexible and efficient.

Preferably, the first transfer device is also adapted for transferringthe toroidal support outward said working station.

The Applicant has noted that using cooling units provided withspecialised stations and with devices for moving the toroidal supportfrom one station to the next one, it is possible to further decrease thework load of the transfer device and at the same time, increase theefficiency of the cooling process and therefore of the whole productionprocess.

The Applicant has further noted that said cooling unit, provided withspecialised stations and with advance devices, also allows buffering anyanomalies of the production cycle since it also acts as a buffer andconsequently, allows eliminating any steps of transfer to stand-bypositions.

It is therefore preferable that the cooling unit comprises at leastthree specialised stations for cooling the toroidal support and it iseven more preferable that each of them is adapted for carrying out afunction different from the functions carried out by the remaining two.

In a preferred embodiment, said specialised stations comprise devicesfor dispensing cooling fluids which are movable and adjustable. In thisway it is possible to adjust the fluid jets in optimum manner accordingto the size and geometry of the toroidal supports.

In particular, at least one of the specialised stations comprises atleast one dispensing device of cooling water or other fluid. In this wayit is possible to use the latent evaporation heat of the fluid forcooling the support.

Advantageously, the first specialised station comprises at least onepair of cooling water dispensing devices which are movable, adjustableand provided with nozzles for nebulizing the water and conveying it atspecific areas of the toroidal support.

In particular, said first specialised station comprises a first pair ofcooling water dispensers for nebulizing the water and conveying it atthe outer surfaces of the toroidal support and a second pair of coolingwater dispensers for nebulizing the water and conveying it at the innersurfaces of the toroidal support.

According to a preferred embodiment, said specialised stations compriseat least a second specialised station including at least one device fordispensing cooling air and preferably at least three devices fordispensing cooling air which are movable and adjustable.

In particular, said cooling air dispensing devices comprise at least onetop dispensing device, one bottom dispensing device and one sidedispensing device for conveying the cooling air respectively on the top,bottom and side surface of the toroidal support.

Advantageously, the cooling unit is provided with at least one devicefor rotating the toroidal support about the axis thereof. Thanks to suchdevice it is possible to obtain homogeneous temperature conditions onthe surfaces of the toroidal support.

Preferably, said cooling unit is provided with a third transfer devicefor the sequential transfer of the toroidal support from one specialisedstation to the next one, which is different from the first and from thesecond transfer device.

Preferably, said third transfer device comprises a conveyor belt whichoperates with a step-by-step movement.

As an alternative, said third transfer device comprises a robotized arm.

Preferably, the removing unit is provided with a dismounting/remountingdevice adapted for dismounting the toroidal support and remounting itafter the tyre has been removed.

Moreover, the cooling unit is advantageously provided with at least onestand-by position for the toroidal supports which may be used indifferent process steps.

Preferably, the stand-by positions of the cooling unit are at least twoand are respectively arranged at the inlet and at the outlet of theworking station.

The tyre production plant may further comprise at least one railoperatively associated with at least one between said first transferdevice and said second transfer device, as well as driving devices formoving the first and the second transfer device.

Advantageously, at least one between said first transfer device and saidsecond transfer device comprises a robotized arm.

Further features and advantages of invention will be clear from thefollowing description of some preferred examples of production plantsand processes according to the invention, made by way of indicating andnon-limiting purpose with reference to the annexed drawings, wherein:

FIG. 1 shows a schematic layout of a plant for producing tyres forvehicle wheels wherein the process according to the present invention iscarried out;

FIG. 2 shows a detail of FIG. 1;

FIG. 3 shows a schematic plan view of a working station, comprising aremoving unit and a cooling unit, of a plant for producing tyres forvehicle wheels according to a first embodiment of the invention during astep of the subject process;

FIG. 4 shows a side view of FIG. 3; and

FIGS. 5 a, 5 b and 5 c show schematic side views of the specialisedstations of a cooling unit of a working station of a plant for producingtyres for vehicle wheels according to one embodiment of the invention.

FIG. 6 shows a “time—temperature” diagram relating to the surface of atoroidal support during the cooling step according to one embodiment ofthe process of the present invention.

With reference to FIG. 1, by reference numeral 1 it is generallyindicated a plant for producing tyres for vehicle wheels according tothe present invention by which the production process according to thepresent invention is carried out.

Plant 1 comprises a building line 2, wherein each tyre is built byassembling structural components according to a predetermined sequence,and a moulding and vulcanization line 3, wherein each green tyre ismoulded and vulcanized, within a respective vulcanization mould, thusbecoming a finished product.

The building line 2 comprises a plurality of building stations 10preferably arranged along a closed loop path indicatively represented byarrows 11 in FIG. 1.

Preferably, said building stations 10 operate simultaneously with eachother, each on at least one tyre for assembling at least one of itsstructural components thereon.

It should be noted that in the present description and in the subsequentclaims, by “structural component” of the tyre it is meant any componentselected for example from: liner, sub-liner, carcass ply/plies, sub-beltinsert, belt strips either crossing over one another or at zero degrees,attachment sheets for the tread band, tread band, rim, bead filler,textile or metallic reinforcing inserts, anti-abrasion insert, or anyportion thereof.

In particular, during the building step the various structuralcomponents used for making each tyre are advantageously engaged on atoroidal support whose shape substantially reproduces the internalconfiguration of the tyre to be obtained. Such a toroidal support has aremovable support shaft adapted for retaining the sectors of which thetoroidal support is formed of. Such type of toroidal support collapsibleor dismountable into a plurality of sectors, so as to be easily removedfrom the tyre when processing is completed, is for example described indocument WO 01/62481 in the name of the Applicant.

Transfer devices 12 operate in the building line 2 for sequentiallytransferring each of the tyres being processed associated with arespective toroidal support from one of the building stations 10 to thenext building station, so as to determine the sequential assembly of allthe tyre components.

Preferably, such transfer devices 12 comprise one or more robotized armsassociated with at least one of the building stations 10 and operatingon the individual toroidal supports for carrying out the sequentialtransfer of each tyre being processed.

According to the present invention, the production plant 1 furthercomprises at least one working station 7 interposed between saidbuilding line 2 and said moulding and vulcanization line 3 and at leasta first transfer device R1 for transferring the moulded and vulcanizedtyre and the respective toroidal support inside working station 7.

Said working station 7 comprises:

-   -   at least one removing unit 5 for removing the moulded and        vulcanized tyre from the respective toroidal support;    -   at least one cooling unit 6 for cooling the toroidal support;        and at least a second transfer device of the toroidal support        R2, different from the first transfer device R1, for        transferring the toroidal support from the tyre removing unit 5        to the toroidal support cooling unit 6.

In the embodiment shown in FIGS. 1 and 2, the working station 7comprises a single removing unit 5, a single cooling unit 6 and onesecond transfer device R2 for transferring the toroidal support from thefirst to the second of said units.

According to a preferred embodiment, the first transfer device R1 isalso adapted for transferring the toroidal support outward the workingstation 7.

The removing unit 5 is adapted for receiving a vulcanized tyre and therespective toroidal support for carrying out the operation of removingthe vulcanized tyre. Within the present scope, by the term “tyreremoval” it is meant at least the set of operations for dismounting thetoroidal support and for removing the tyre from the above dismountedtoroidal support.

According to a preferred embodiment, said second transfer device R2 isobtained by a handling device 4, illustrated in FIG. 4, also adapted forextracting and inserting said support shaft of the toroidal support soas to allow the latter to be respectively disassembled in a plurality ofsectors and reassembled in its operating toroidal shape.

According to a further alternative embodiment, the removing unit 5comprises a device SR1 for dismounting/remounting the toroidal supportwhich allows removing the moulded and vulcanized tyre from the toroidalsupport and remounting the toroidal support itself after the tyreremoval.

With particular reference to FIGS. 3 and 4, it is shown that the coolingunit 6 comprises at least three specialised stations 6A, 6B and 6C, eachspecialised in carrying out a specific step of the cooling of thetoroidal support.

According to a preferred embodiment, each of said specialised stations6A, 6B, 6C is adapted for performing a function that differs from thefunctions performed by the remaining two.

FIGS. 5A, 5B and 5C show that said specialised stations 6A, 6B, 6C areprovided with special dispensing devices 13, 14, 15, 16, 17 of coolingfluids.

In particular, the cooling unit 6 comprises a first specialised station6A including at least one dispensing device 13, 14 of cooling water orother service fluids.

In the embodiment shown in FIG. 5A, said first specialised station 6Acomprises two pairs of cooling water dispensing devices 13, 14. Suchdevices 13, 14 are movable, adjustable and provided with nozzles fornebulizing the water and conveying it at specific areas of the toroidalsupport.

In particular, a first pair of cooling water dispensers 13 conveys thecooling water at the outer surfaces of the toroidal support and a secondpair of cooling water dispensers 14 conveys the water at the innersurfaces of the toroidal support.

The cooling unit 6 of the production plant 1 also comprises a secondspecialised station 6B which includes devices 15, 16, 17 for dispensingcooling air or other service fluids.

In the embodiment shown in FIG. 5B, the second specialised station 6Bcomprises three cooling air dispensing devices 15, 16, 17: a topdispensing device 15, a bottom dispensing device 16 and a sidedispensing device 17 for conveying the cooling air respectively on thetop, bottom and side surface of the toroidal support.

Said cooling air dispensing devices 15, 16, 17 are preferably movableand adjustable in a manner similar to the cooling water dispensingdevices 13, 14.

The cooling unit 6 is further provided with one or more temperaturesensors 18 arranged in one or more of the specialised stations 6A, 6B,6C, adapted for monitoring the thermal trend of the toroidal supportsduring the production process according to the present invention.

The cooling unit 6 is further provided with at least one rotation device19 adapted for rotating the toroidal support about the axis thereofwhile cooling.

The cooling unit 6 is finally provided with a third transfer deviceadapted for carrying out the sequential transfer of the toroidal supportfrom one specialised station 6A, 6B, 6C to the next one, which isdifferent from the first transfer device R1 and from the second transferdevice R2.

Such third transfer device comprises a conveyor belt preferablyoperating with a step-by-step movement for transferring the toroidalsupport at predetermined frequencies from one specialised station 6A,6B, 6C to the next one. In this way, the cooling unit 6 is a tunnelwherein the toroidal supports run according to a travelling directionindicated by arrows 22 in the figures.

Alternatively, said third transfer device comprises a robotized arm thatpicks up the toroidal support from one specialised station 6A, 6B, 6Cand moves it to the next one.

According to an embodiment of the present invention, the productionplant 1 is provided with a transport device 21 adapted for transportingthe moulded, vulcanized tyre removed from the relevant toroidal support,outward the working station 7.

The cooling unit 6 may be provided with one or more stand-by positions20 of the toroidal supports adapted for the temporary storage of thetoroidal supports.

Preferably, said stand-by positions 20 are two and are respectivelyarranged at the inlet and at the outlet of the working station 7.

The production plant 1 further comprises at least one rail operativelyassociated with the first transfer device R1 and/or to the secondtransfer device R2.

In the embodiments shown in FIGS. 2 and 3, plant 1 is provided with apair of rails which make up a track 9 on which the first transfer deviceR1 travels.

The production plant 1 further comprises driving devices, not shown inthe figures, for moving the first transfer device R1 and the secondtransfer device R2.

At least one between said first transfer device R1 and said secondtransfer device R2 comprises a robotized arm. In the embodiments shownin the figures, R1 comprises a robotized arm.

The vulcanization line 3 comprises at least one unit for vulcanizing thegreen tyre provided with six vulcanization moulds.

Preferably, the vulcanization moulds are mounted on a turntable to bedriven in rotation so as to make the same vulcanization moulds carry outa closed-loop path, sequentially carrying them, one after the other, toa tyre loading/unloading station, each associated with its own toroidalsupport.

In this way, a green tyre, after having been loaded into a vulcanizationmould, is subjected to a moulding and vulcanization process and, oncethe suitable time to complete the moulding and vulcanization operationshas been achieved, is unloaded from the mould at the sameloading/unloading station through rotation of the turntable.

The vulcanization moulds are preferably sealed airtight and are arrangedto house a tyre being processed previously built on a toroidal support,the outer surface of which substantially reproduces the internalconfiguration of the tyre to be obtained. Said vulcanization moulds areprovided with working fluid passage devices as illustrated for examplein WO 2004/045837, in the name of the same Applicant.

If required by production requirements, it is possible to design thevulcanization line 3 so as to comprise two vulcanization units. In thiscase it is possible but not necessary to provide two working stations 7or a single working station 7 provided with two removing units and/ortwo cooling units 6.

With reference to the production plant 1 illustrated in FIGS. 1-5C, apreferred embodiment of a production process according to the inventionshall now be described.

In accordance with a first step a), a green tyre is assembled on arespective toroidal support assembling each structural component of thetyre according to a predetermined sequence at the above buildingstations 10 of the building line 2 of the production plant 1.

This building step of each tyre is carried out for example according tomethods illustrated in document WO 01/32409, in the name of the sameApplicant.

At the end of the building step, the tyre production process accordingto the present invention provides the performance of a step b) ofmoulding and vulcanizing the green tyre in the vulcanization line 3 ofthe production plant 1 so as to define the structure of the tyreaccording to the desired geometry and tread pattern.

Afterwards, the process according to the present invention provides astep c) of transferring the toroidal support and the relevant tyrevulcanized in the aforesaid working station 7 comprising the removingunit 5 of the tyre from the respective toroidal support and the coolingunit 6 for cooling the toroidal support. Said step c) is carried out bythe above first transfer device R1.

In the removing unit 5 of the working station 7, the tyre is removedfrom the relevant toroidal support in a step d) that comprises thedismounting of the toroidal support and the removal of the moulded andvulcanized tyre from said toroidal support; Preferably said step d) alsocomprises the subsequent remounting of the toroidal support, which istherefore ready for a new production cycle.

At this point, the step e) of transferring the toroidal support from theremoving unit 5 into the cooling unit 6 is carried out by a secondtransfer device R2 different from said first transfer device, saidsecond transfer device R2 preferably comprising said handling device 4.

In accordance with the process according to the present invention, thestep f) of cooling the toroidal support is carried out in said coolingunit 6.

Once the toroidal support has been cooled, it is transferred outward theworking station 7, in accordance with a step g), preferably by means ofthe first transfer device R1.

In particular, the step f) of cooling the toroidal support comprises thefollowing steps:

f1) cooling the toroidal support to a temperature comprised betweenabout 100° C. and about 110° C.;f2) cooling the toroidal support to a temperature comprised betweenabout 55° C. and about 65° C.;f3) cooling the toroidal support to a temperature suitable for the tyrebuilding process;

In accordance with a preferred embodiment, step f3) comprises coolingthe toroidal support to a temperature comprised between about 40° C. andabout 50° C.

Preferably, step f1) is carried out by means of cooling water at atemperature comprised between about 10° C. and about 20° C. and one orboth steps f2) and f3) are carried out by cooling air at a temperaturecomprised between about 3° C. and about 10° C.

As shown in FIG. 5A, the cooling water is nebulized and sprayed at theouter surface and at the inner surface of the toroidal support.

On the other hand, FIGS. 5B and 5C show how the cooling air is dispensedat the top surface, the bottom surface and the outer surface of thetoroidal support.

The process for producing tyres according to an embodiment of thepresent invention provides that the step e) of cooling the toroidalsupport comprises the sequential transfer of the toroidal support in atleast three specialised stations 6A, 6B, 6C differing one from theother.

Preferably, said sequential transfer of the toroidal support takes placeby a third transfer device different from the first transfer device R1and from the second transfer device R2, said third transfer devicecomprising a conveyor belt or a robotized arm.

According to a further alternative embodiment, the sequential transferof the toroidal support from one specialised station 6A, 6B, 6C to thenext one is carried out by the first transfer device R1. In that case,the cooling unit 6 is not configured as a tunnel.

The step d) of removing the moulded and vulcanized tyre from therelevant toroidal support in said removing unit 5 comprises the stepsof:

d0) extracting the support shaft of the toroidal support;d1) dismounting the toroidal support;d2) separating the vulcanized tyre from the toroidal support;d3) remounting the toroidal support;d4) inserting said support shaft into the remounted toroidal support.

Preferably, steps d0) and d4) are carried out by the second transferdevice R2 in the embodiment of the handling device 4.

Preferably, steps d1), d2) and d3) are carried out by the above deviceSR1 for dismounting/remounting the toroidal support.

At least one between step d1) of dismounting the toroidal step and stepd2) of remounting of the toroidal support is carried out by the abovehandling device 4. As an alternative, at least one between said stepsd1) and d2) is carried out by the second transfer device R2.

Once the cooled toroidal support has been transferred outward theworking station 7 in accordance with step g), it is possible to providea step h) of introduction of the toroidal support into the building line(2) for building a further tyre.

FIG. 6 shows a diagram of the surface temperature of a toroidal supportas a function of the cooling time elapsed according to one embodiment ofthe process of the present invention.

In such figure, by “t” it is indicated the cooling time—expressed inseconds (sec.)—and by “T” the surface temperature—expressed in ° C.—of atoroidal support subject to the process according to one embodiment ofthe present invention.

In particular, by “to” it is indicated the start time of the coolingstep f) that coincides with the beginning of step f1), “t1” the starttime of step f2), “t2” the start time of step f3) and by “t3” the starttime of step f3) that coincides with the end of step f).

In a tyre production process for motorcycle wheels, according to oneembodiment of the present invention, carried out in a production plant1, of the type illustrated in FIGS. 1-5C, if t0=0 sec., t1=about 90sec., t2=about 180 sec. and t3=about 270 sec.

In the scope of the present previous description and the followingclaims, all the numerical measurements indicating quantity, parameters,percentages, etc, are to be considered as preceded by the term “about”,unless otherwise specified. Furthermore, all the intervals of numericalmeasurement include all the possible combinations of the maximum andminimum numerical values, as well as all the possible intermediateintervals, as well as those specifically indicated in the text.

1-48. (canceled)
 49. A process for producing a tyre for a vehicle wheelcomprising the steps of. a) building a tyre on a toroidal support in abuilding line of a production plant; b) moulding and vulcanizing saidbuilt tyre in a vulcanization line of said production plant to produce amoulded and vulcanized tyre; c) transferring by means of a firsttransfer device the toroidal support and the moulded and vulcanized tyreto a working station comprising a removing unit for removing the tyrefrom the respective toroidal support and a cooling unit for cooling thetoroidal support; d) removing the moulded and vulcanized tyre from thetoroidal support in said removing unit; e) transferring the toroidalsupport from said removing unit to said cooling unit by means of asecond transfer device different from said first transfer device; and f)cooling the toroidal support in said cooling unit.
 50. The process forproducing a tyre for vehicle wheels according to claim 49, comprising,after cooling the toroidal support in step f); g) transferring thecooled toroidal support outward the working station by means of thefirst transfer device.
 51. The process for producing a tyre for avehicle wheel according to claim 49, wherein step f) of cooling thetoroidal support comprises the sub-steps of: f1) cooling the toroidalsupport to a temperature of about 100° C. to about 110° C.; f2) coolingthe toroidal support to a temperature of about 55° C. to about 65° C.;and f3) cooling the toroidal support to a temperature suitable for thetyre building process.
 52. The process for producing a tyre for avehicle wheel according to claim 51, wherein step f3) comprises coolingthe toroidal support to a temperature of about 40° C. to about 50° C.53. The process for producing a tyre for a vehicle wheel according toclaim 51, wherein step f1) is carried out by means of cooling water. 54.The process for producing a tyre for a vehicle wheel according to claim53, wherein the cooling water has a temperature of about 10° C. to about20° C.
 55. The process for producing a tyre for a vehicle wheelaccording to claim 53, wherein the cooling water is nebulized andsprayed at the outer surface and at the inner surface of the toroidalsupport.
 56. The process for producing a tyre for a vehicle wheelaccording to claim 53, wherein at least one of steps f2) and f3) iscarried out by means of cooling air.
 57. The process for producing atyre for a vehicle wheel according to claim 56, wherein both steps f2)and f3) are carried out by means of cooling air.
 58. The process forproducing a tyre for a vehicle wheel according to claim 56, wherein thecooling air has a temperature of about 3° C. to about 10° C.
 59. Theprocess for producing a tyre for a vehicle wheel according to claim 56,wherein the cooling air is dispensed at a top surface, at a bottomsurface and at an outer surface of the toroidal support.
 60. The processfor producing a tyre for a vehicle wheel according to claim 49, whereinstep f) of cooling the toroidal support in said cooling unit comprisessequential transfer of the toroidal support in at least threespecialised stations, each station differing from the other stations.61. The process for producing a tyre for a vehicle wheel according toclaim 60, wherein the sequential transfer of the toroidal support fromone specialised station to the next is carried out by a third transferdevice different from the fast transfer device and from the secondtransfer device.
 62. The process for producing a tyre for a vehiclewheel according to claim 61, wherein said third transfer devicecomprises a conveyor belt
 63. The process for producing a tyre for avehicle wheel according to claim 61, wherein said third transfer devicecomprises a robotized arm.
 64. The process for producing a tyre for avehicle wheel according to claim 60, wherein the sequential transfer ofthe toroidal support from one specialised station to a next specializedstation is carried out by the first transfer device.
 65. The process forproducing a tyre for a vehicle wheel according to claim 49, wherein stepd) of removing the moulded and vulcanized tyre from the toroidal supportin said removing unit comprises the sub-steps of: d1) extracting asupport shaft of said toroidal support; d2) dismounting the toroidalsupport; d3) separating the vulcanized tyre from the toroidal support;d4) remounting the toroidal support; and d5) inserting said supportshaft into the remounted toroidal support.
 66. The process for producinga tyre for a vehicle wheel according to claim 65, wherein at least oneof steps d1) to d5) is carried out by said second transfer device. 67.The process for producing a tyre for a vehicle wheel according to claim65, wherein at least one of steps d2), d3) and d4) is carried out by adevice for dismounting/remounting the toroidal support.
 68. The processfor producing a tyre for a vehicle wheel according to claim 50, whereinstep g) of transferring the cooled toroidal support outward from theworking station is followed by step h) of introducing the toroidalsupport into said building line for building another tyre.
 69. A plantfor producing tyres for vehicle wheels comprising: a line for building agreen tyre on a respective toroidal support; a line for moulding andvulcanizing the tyre; at least one working station interposed betweensaid building line and said moulding and vulcanization line; and atleast a first transfer device for transferring the moulded andvulcanized tyre and a respective toroidal support into said workingstation, wherein said working station comprises: at least one removingunit for removing the moulded and vulcanized tyre from the respectivetoroidal support; at least one cooling unit for cooling the toroidalsupport; and at least a second transfer device of the toroidal support,different from the first transfer device, for transferring the toroidalsupport from the tyre removing unit to the toroidal support coolingunit.
 70. The plant for producing tyres for vehicle wheels according toclaim 69, wherein the first transfer device is capable of being adaptedfor transferring the toroidal support outward said working station. 71.The plant for producing tyres for vehicle wheels according to claim 69,wherein the cooling unit comprises at least three specialised stationsfor cooling the toroidal support.
 72. The plant for producing tyres forvehicle wheels according to claim 71, wherein each of said specialisedstations is capable of being adapted for performing a function thatdiffers from functions performed by the other two specialised stations.73. The plant for producing tyres for vehicle wheels according to claim71, wherein said specialised stations comprise dispensing devices fordispensing cooling fluids.
 74. The plant for producing tyres for vehiclewheels according to claim 71, wherein said specialised stations compriseat least a first specialised station comprising at least one coolingwater dispensing device.
 75. The plant for producing tyres for vehiclewheels according to claim 74, wherein said first specialised stationcomprises at least one pair of cooling water dispensing devices whichare movable, adjustable and provided with nozzles for nebulizing waterand conveying the water at specific areas of the toroidal support. 76.The plant for producing tyres for vehicle wheels according to claim 75,wherein said first specialised station comprises a first pair of coolingwater dispensers for nebulizing the water and conveying the water atouter surfaces of the toroidal support and a second pair of coolingwater dispensers for nebulizing the water and conveying the water atinner surfaces of the toroidal support.
 77. The plant for producingtyres for vehicle wheels according to claim 71, wherein said specialisedstations comprise at least a second specialised station comprising atleast one cooling air dispensing device.
 78. The plant for producingtyres for vehicle wheels according to claim 77, wherein said secondspecialised station comprises at least three cooling air dispensingdevices, which are movable and adjustable.
 79. The plant for producingtyres for vehicle wheels according to claim 78, wherein said cooling airdispensing devices comprise at least one top dispensing device, onebottom dispensing device and one side dispensing device for conveyingthe cooling air respectively on a top, bottom and side surface of thetoroidal support.
 80. The plant for producing tyres for vehicle wheelsaccording to claim 69, wherein said cooling unit is provided with atleast one temperature sensor.
 81. The plant for producing tyres forvehicle wheels according to claim 71, wherein each specialised stationis provided with a temperature sensor.
 82. The plant for producing tyresfor vehicle wheels according to claim 69, wherein said cooling unit isprovided with at least one device for rotating the toroidal supportabout an axis thereof.
 83. The plant for producing tyres for vehiclewheels according to claim 71, wherein said cooling unit is provided witha third transfer device for the sequential transfer of the toroidalsupport from one specialised station to a next specialized station, saidthird device being different from the first transfer device and from thesecond transfer device.
 84. The plant for producing tyres for vehiclewheels according to claim 83, wherein said third transfer devicecomprises a conveyor belt.
 85. The plant for producing tyres for vehiclewheels according to claim 84, wherein said conveyor belt transfers thetoroidal support from one specialised station to the next specializedstation with a step-by-step movement.
 86. The plant for producing tyresfor vehicle wheels according to claim 83, wherein said third transferdevice comprises a robotized arm.
 87. The plant for producing tyres forvehicle wheels according to claim 71, wherein said first transfer deviceis capable of being adapted for the sequential transfer of the toroidalsupport from one specialised station of the cooling unit to the nextcooling unit.
 88. The plant for producing tyres for vehicle wheelsaccording to claim 69, wherein said removing unit is provided with adismounting/remounting device capable of being adapted for dismountingthe toroidal support and remounting the toroidal support after a tyrehas been removed.
 89. The plant for producing tyres for vehicle wheelsaccording to claim 69, wherein said second transfer device comprises ahandling device capable of being adapted for extracting a support shaftfrom the toroidal support and inserting the support shaft in thetoroidal support.
 90. The plant for producing tyres for vehicle wheelsaccording to claim 69, wherein said cooling unit further comprises atleast one stand-by position for the toroidal supports.
 91. The plant forproducing tyres for vehicle wheels according to claim 90, comprising atleast two stand-by positions respectively arranged at an input and at anoutput of the working station.
 92. The plant for producing tyres forvehicle wheels according to claim 69, further comprising at least onerail operatively associated with at least one of said first transferdevice and second transfer device.
 93. The plant for producing tyres forvehicle wheels according to claim 69, wherein at least a pair of railsform at least one track upon which the first transfer device moves. 94.The plant for producing tyres for vehicle wheels according to claim 69,further comprising driving devices for moving the first transfer deviceand the second transfer device.
 95. The plant for producing tyres forvehicle wheels according to claim 69, wherein at least one of said firsttransfer device and said second transfer device comprises a robotizedarm.
 96. The plant for producing tyres for vehicle wheels according toclaim 69, further comprising at least one transport device capable ofbeing adapted for transporting a tyre removed from the toroidal support,outward the working station.